Insights on ecological and reproductive aspects of two cryptogenic peracarid crustaceans from Argentinean coasts

FRICKE, A.; BIANCALANA, F; TONICELLI, G.; BERASATEGUI, A.; KOPPRIO, G.; GAUNA, M.C.; PARODI, E.R.

BRAZILIAN JOURNAL OF OCEANOGRAPHY

INST OCEANOGRAFICO

Lugar: São Paulo; Año: 2015 p. 194 - 206

1679-8759

Peracarid crustaceans belong to the most important agglomerating macrofauna in sedimentary habitats. The amphipod Monocorophium insidiosum CRAWFORD, 1937 and the tanaid Tanais dulongii AUDOUIN, 1926 are listed as invasive species. In the present study we investigated the ecology of M. insidiosum and T. aff. dulongii on the Argentinian coast. We bred both crustaceans to study their fecundity and growth, and investigated their behavior and potential interspecific relations in four different laboratory experiments. We evaluated tube building capabilities experiment 1), and tested gender specific responses of M. insdiosum to empty (experiments 2 and 3), and housed (inhabited?) T. aff. dulongii tubes (experiment 4). Our results showed high fecundity (three generations within four weeks) and growth rates (duplication of body lengths in two weeks) for M. insidiosum. Two tube construction strategies were distinguished: a tube changing behavior for M. insidiosum, showing greater construction activity on the part of females, and tube keeping behavior on the part of T. aff. dulongii. Overall, tanaid tubes were frequently claimed by M. insidiosum, demonstrating a close interspecific relationship and resulting in decreased sediment aggregating activity. In the light of our observations it may be affirmed that these invasive species are probably frequently distributed along the Patagonian Atlantic coast and will spread still further in the future.